Rock-drill



J. F. ALLEN.

ROCK DRILL.

(No Model.)

Patented Nov. 7, 1882 UNITED STATES PATENT OFFICE.

JOHN F. ALLEN, OF BROOKLYN, NEW YORK ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 267,127, dated November7, 1882. Application filed February 6, 1882. (No model.)

To all whom it may concern:

Be it known that I, JOHN F. ALLEN, of Brooklyn, in the State of NewYork,a citizen of the United States, have invented a new and usefulImprovement in Rock-Drills, of which the following is a specification.

In rock-drilling machines the cylinder-piston, to which thedrilling-tool is attached is after each stroke turned partly around.This operation is generally performed by means of a central bolt havinginclined or twisted feathers or ribs on its circumference working into acorrespondingnut attached into the piston, said bolt being heldstationary when the piston moves in one direction, whereby said pistonis forced to follow the inclination of the ribs on said bolt, and isconsequently turned partly around, corresponding to the twist orinclination of the feathers, while when the piston moves in the oppositedirection this bolt is let loose and free, whereby the piston moves in astraight line and causes the bolt to turn. This alternate operation ofholding the bolt stationary and allowing the same to turn freely isgenerally produced by the arrangement of pawls acting against a serratedwheel firmly attached to the bolt.

My invention consistsin the arrangement of a number of disks or platesalternately held stationary in a suitable case, and held fast on thebolt, and acted upon by a suitable collar or washeron said bolt,uponwhich the pressure of the cylinder operating the piston is made to actto press the several disks or plates together, whereby the frictionproduced between these several disks will prevent the disks attached tothe bolt, and consequently the bolt, from turning, while as soon as thepressure is removed the bolt can turn freely around again.

In the accompanying drawings, Figure I represents a horizontal sectionat line 2 z, Fig. 11, and Fig. II is a vertical section of part of arock-drill with my improvement attached.

A represents part of a cylinder of a rockdrill; B, the piston working inthe same, and O the bolt, havinginclined or twisted feathers on itslower end, which projects into the cylinder and works in a correspondingnut, 0, fastened into the piston B.

D is a case forming the top or cover of the cylinder, and E the cover ofthe same. The

bolt 0, above the feathered part, is made circular atK, and fittedsteam-tight into thelower part of the casing D. Above that part, at G,

In the inner periphery of the casing D projections J are provided,whereby disks orplates n it, placed loose into the case D, are heldstationary. The central holes of these plates are made of suflicientsize toallow the squared part G of the bolt 0 to turn freely in thesame. Alternately between these disks n n disks aaare placed upon thesquared part G of the bolt 0, and of such a diameter as to be able toturn freely, with the bolt 0, inside of the projections J. These disks nand a are made of any desired number, and of a thickness to fill thespace between the bottom of the case D and the under side of the washer,flange, or collar H of the bolt 0, which said collar Hrests upon the topplate or disk and tits tight, capable of turning in the case D. Theunder side of the coverE is provided with a circular recess, 20,connected through passages 17 o with the cylinder A, below the bottom ofthe piston B, or with the passage-way leading to the lower part of thecylinder. When the pressure is upon the top of the piston B and thepiston moves downward the lower end of the cylinder, and consequentlythe passages 11 c and recess w, are in connection with the exhaust, andno pressure will be exerted upon the collar H, and through the same uponthe disks n and a, in consequence of which the disks a a and bolt 0 willbe free to be turned around by the piston B, or by the nut G, attachedto the same. As soon as pressure is admitted below the piston B the samewill likewise pass through the passages 12 o into the recess 10, andwill act upon the top of the collar H, forcingthereby the same tightupon the disks n and a, whereby friction between the several disks willbe produced, and as one-half of said disks a a are fitted to the squaredpart G of the bolt 0 said bolt will beheld stationary, and its lowerfeathered or ribbed part will cause the piston B to turn partiallyaround the desired distance, corresponding with the inclination of theribs or feathers. When it is desired. to turn thepiston B during itsdownward motion the inside of the case D is connected with the upperpart of the cylinder, so that the pressure acting upon the piston 13 tomove the same downward will act against the collar H and disks n and ato produce the desired friction between the disks, and thus hold thedisks a a, and con- 'seqnently the bolt 0, stationary during that partof the movement of the piston B, in the manner above described.

Instead of making a flange or collar, H, on the bolt 0 to bear upon'theseries of disks, a washer fitting tight around the bolt 0, and in theinside ofthc case D, may be arranged, similar to a piston, against whichthe pressure is made to act.

What I claim as my invention, and desire to secure by Letters Patent,is-

In a rock-drill provided with a central bolt connected to a suitable nutattached to the pis ton, or to the piston itself, for the purpose ofturning said piston partly around when moving in one direction, a seriesof disks, (1 a, attached to the central bolt, 0, in combination withalternate stationary disks, n n, and recess w, connected throughsuitable passages with the end of the cylinder of the rock-drill,arranged to operate in the manner and for the purpose substantially asherein described.

JOHN F. ALLEN.

Witnesses:

HENRY E. ROEDER, J. B. N ONES.

